Muffler for internal-combustion engines



June 3, 1930. c. s. WATKINS MU FFLER FOR INTERNAL COMBUSTION ENGINE$ Filed Oct. 19, 1928 gwuzniot CYAYm/v 5. VVAr/r/ms.

Patented June 3, 193i) Fl lfilil CLAYTON S3. VIAEKINS, F AMARILLQ, TEXAS MUFFLER F03 INTEBNAL-CDEIBUSTION ENGINES Application filed October 19, 1028. Serial No. 313,559.

3 sure and thereby increase the etliciency of the engine.

Attempts have been made to avoid back pressure, but so far as I am aware, all such attempts have resulted in decreased inul'ller eiliciency, or have increased the fire hazard.

According to my invention I provide means for releasing pressure at a point or points substantially nearer the engine than the mutiler proper, and also provide means for releasing pressure within the muffler as it occurs.

The invention will be more readily understood by reference to the accompanying drawings showing certain illustrative embodiments of the invention.

In the drawings Fig. 1 is a horizontal sectional view showing a muffler equipped with the improved pressure release and extraction tube.

Fig. 2 is a detail View on an enlarged scale showing one end of the release tube.

Fig. 3 is a view taken on line 33 of Fig. 2 looking in the direction of the arrows.

Fig. 4 is a sectional view on line 4. 4 of 1, and

Fig. 5 is a detail view similar to Fig. 2 but showin a modification.

As shown in the drawings, A denotes the exhaust pipe of an internal combustion engine; the portion designated by B denotes a suitable muffler, which, according to the broadest scope of my invention, may be of any desired construction, while the portion designated C denotes a flaring intermediate conduit connecting muffler B with the exhaust pipe.

lVith mufflers as now constructed, a back pressure is accui'nulated within the exhaust pipe prior to the first baille of the inui'lier, which pressure seriously impairs the eiilciency of the engine. In order to eliminate this back pressure I have provided a pro sure release tube D tapering from a point E located substantially prior to the nnili ler, to the outlet end of the mufiier. The tube D is closed at the smaller end toward th ex iaust pipe, but open at the end F, and is provided with a plurality of openings which are protected from the direct force of exploding :es by means of cones 11, suitably secured to the tube D as by welding. Th se cones are at an angle substantially equal to the flare of the outer casing C, and are small enough so that no obstruction is offered to the passage at gases prior to their entrance into the muiller proper. The flaring ot the casing C compensates for the pressure of the cones 11, so that there is no restriction in area. Preferably cone shaped members 12, flared oppositely to the cones 11, and provided with apertures 13, serve to further protect the openings 11 against the direct force of exploding gases. A modification is shown in Fig. 5 in which openings 14% are formed in the tube D, which are protected by struck up portions 15 integral with the tube. The function of the cones 11 or he struck up portions 15 is to defleet the explosive gases from the openings in the tube D so that no pulsations are trans mitted through the tube while still permitting any excess pressure existing above the muliier to be gradually released into the tube D opening at F.

While I do not wish to be limited to de "ails of construction of the niuilier, or oi the pressure release tube, I have shown a form of device which may be made at small cost, which is efficient in its operation and which may be readily applied to the exhaust pipe of an in ternal combustion engine. As shown, the outor shell B of the mui'ller and the flaring con nectine' portion C are made welded together at 16, therebeing provided an inner ring or battle 17 secured to either the shell 13 or C prior to the welding together of these two members. The ring 17 forms the first battle of the muffler proper. The remaining batlles of the muffler consist of cones 18 located at intervals along the tube D beyond. the cones 11, while between adjacent cones 18 are located rings 19 extending inwardly from a sleeve 20, located within an outer shell 21 and spaced therefrom by any suitable means, as spiders 22. The cones 18 and rings 19 cause the explosion gases to flow by a zig zag path,

thereby breaking the force of the explosion and muillino' the sound. The cones 18 incline outwardly from the tube D at a moon greater angle than the cones 11 and extend. greater distance from the tube D than the cones 11, so that while the cones produce no mutliing action whatever, the cones 18 in combination with the rings 19 produce a very eiiicient muiliing' action.

V-Jhile perforations 10 in the portion 01" the tube D nearer to the engine than the mother provide for the release of back pressure produced by the first bullies oi the mullet, it is desirable to provide turthcr means for releasing any pressure which may exist within the i'nuiiier. Consequently, apertures 23 in the tube are Inovided beneath the cones 18, while similar pertorations are provided beneath the rings 19. The perforations 23 allow the pressure to release into the tube D while the perforations 24 release into the annular chamber between the inn-er sleeve 20 and the outer shell 21. A small annular passage is left between the first bathe 17 and the end of the sleeve 20, which performs the same function as the apertures 24.

la order to permit of assei'nbling the device th sleeve 20 may be made in two semi-cylindrical parts, the two parts carrying complementary l l s of the battle rings 19. The two halves of the sleeve are then fitted together over the lower end of the tube D, which tube is provided with the cones 11 and 19, and apertures 10 and 23. The halves of the sleeves may be s cured together by welding as at or by bolting together complementary flanged portions. Suitable spacers 27 are provided between the sleeve 20 and the tube D.

The sleeve 20 and tube D having been assembled, they are now inserted and secured in place within the outer shell 21 and the connecting member C, spacing members 22 and ill) respe :tively being provided to space the sleeve 20 from the shell 21 and the tube D from, the outer member C. The combined niul'l'ler, 111' member form a detachable unit which may b secured to the exhaust pipe A in any sui .ibl manner, as by flanges 31.

Operation hen the device has been assembled and secured to the exhaust pipe, as above described, an explosion from the engine coming through the exhaust pipe A passes through the tapered pipe C without increasing the pressure until the first bail ie 17 is met ith. The battles 17 1S and 19 whichaccomplish the mufi'ling operation normally tend to produce a back iressure. This pressure, however, is released through the apertures 10 into the pressure release tube D, the cones 11 and 12 preventing the pulsations of the explosion from being transmitted into the tube D. Any excess pressure which tends to be prosure release tube and connecting duced within the mufller itself is released almost as rapidly as it formed through the apertures 28 into the tube D and through apertures and 26 into the annular Cl'llll'lbQl' 25 between the sleeve 20 and the shell 21. The force of the explosi is largely disipated in passing between the babies 17, 1S and. 19, but such force as it still possesses as it leaves the muiiler outlet tends to reduce the pressure *ithin the tube D and the chamber the exhaust gases from the muiller exerting; sort of sucking or extracting action. This reduced pressure Within the tube D renders the tube even more etlicient in rcleasing; any back pressure tending); to form either above or Within the .n'iu'lilor.

hat I. claim is In combination with a mutiler for internal combustion engines, means tor releasing pressure prior to the muilier, comprising a flan ing tube extending longitudinally through StlCl111l1filG1,l1llVll1g an open end at the muttler outlet, a d having a portion extending beyond the mutl'ler toward the engine, said portion being apertured to permit pressure to release into the tube, :1 id. cones secured to said tube for protecting the apertures from the direct force of an explosion.

In testimony whereof I afiix my siu'nature.

CLAYTON S. ll A KlNS.

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